Shotgun bore reducer



May 28, 1968 T. R. THOMAS 3,384,989

SHOTGUN BORE REDUCER Filed July 21, 1966 Shell l4 Fig.6

Thurman R. Thomas INVENTOR.

United States Patent 3,384,989 SHOTGUN BORE REDUCER Thurman R. Thomas,421 Wright St, High Point, N.C. 27260 Filed July 21, 1966, Ser. No.566,823 2 Claims. (Cl. 4277) ABSTRACT OF THE DISCLOSURE A bore reducerfor shotgun barrels which adapter may be substantially the length of ashell normally utilized in a shotgun or a length sufiicient to extendsomewhat more than the entire length of the shotgun barrel within whichit is utilized, whereby bore reducers constructed in accordance with theinvention may be utilized in conjunction with shotguns of varying typesand configurations including shotguns provided with shell receivingmagazines. In this regard, one embodiment of a bore reducer disclosedherein is utilized in conjunction with each shell of a gauge lesser thanthat normally accommodated by the shotgun, thereby permitting theloading of the shotgun magazine with shells of a gauge lesser than thatnormally utilized in conjunction with the shotgun. Thus, the shells ofthe lesser gauge can be automatically transported to the firing chamberof the gun in the same manner as if they were actually shells of a gaugenormally utilized in the gun. In the embodiment of the inventionutilizing a reducer of somewhat greater length than the barrel of thegun the reducer is secured within the gun by a threadably engaged collarreceived on a portion of the reducer extending outwardly from the muzzleof 'the gun which embodiment further includes a spent shell extractormeans adapted to cooperate with an extractor means provided in the gun.

The present invention relates to bore reducers for shotgun barrels, andmore particularly to tubular members which may selectively be utilizedin conjunction with break-action, automatic or bolt action shotguns soas to adapt the shot gun to fire smaller gauge shells than wouldnormally be utilized in the gun.

More particularly, the present invention contemplates the provision ofbore reducers which may vary in length from the approximate lentgh of ashotgun shell to somewhat slightly more than the full length of the gunbarrel so as to provide a maximum of flexibility whereby a singleshotgun may be advantageously adapted for a particular type of shooting,be it for game, trap shooting or target practice, for example.

Numerous sohtgun bore reducers have been proposed heretofore to permitthe use of smaller gauge shells than normally utilized in the gun. Aswill become apparent hereinafter most of these bore reducing devices arenot adapted to be utilized in automatic or bolt action shotguns nor arethey adapted to protect the entire length of the bore of the gun so asto insure that, for example, the bore of the gun is not adverselyaffected when firing shells of a lesser gauge than normally utilized.

Accordingly, it is a primary object of the present invention to providean improved shotgun bore reducer which overcomes the inherentdisadvantages associated with bore reducers proposed heretofore.

It is another object of the present invention to provide a shotgun borereduc'er constructed in accordance with the principles of the presentinvention wherein separate exemplary embodiments of the bore reducer mayadvantageously be utilized in conjunction with either a breakactionbreech-loading shotgun or an automatic shotgun, such as provided with amagazine feed means, so as to facilitate the utilization of the gun toautomatically fire shells of a lesser gauge than normally utilized inthe gun.

3,384,989 Patented May 28, 1968 A further object of the presentinvention is to provide an exemplary embodiment of a shotgun borereducer constructed in accordance with the principles of the presentinvention particularly adapted to be placed within the shotgun barreland extend from the breech of the barrel along the entire length thereofand project outwardly somewhat from the muzzle of the barrel so as tofacilitate releasably securing the reducer within the barrel of theshotgun to preclude the possibility of adversely affecting the innersurfaces of the shotgun barrel when firing shells of lesser gauge ordiameter than normally used in the gun.

Stlll another object ofthe present invention is to provide shotgun borereducers constructed in accordance with the principles of the presentinvention which are so designed so as to fit within the shotgun bore tobe reduced in such a manner as to minimize the possibility of unduevibration, rupturing or distortion of the bore reducer in use.

Still another object of the present invention is to provide shotgun borereducers which are extremely simple in construction, relativelyinexpensive to manufacture and easy to operatively position within ashotgun.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing bad to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a fragmentary side elevational view of a break-actionbreech-loading single barrel shotgun with portions of the barrel, stockand firing mechanism broken away to show certain interior details aswell as the operative placement of one embodiment of a bore reducerconstructed in accordance with the principles of the present invention;

FIGURE 2 is a rear perspective view, as seen from the breech end, of theshotgun bore reducer of FIGURE 1;

FIGURE 3 is an elevational view of another embodiment of a shotgun borereducer constructed in accordance with the principles of the presentinvention wherein there is provided a bore reducer of somewhat greaterlength than the barrel of the gun with which it is to be utilized andfurther showing a portion of the muzzle end of the reducer in section;

FIGURE 4 is an enlarged fragmentary longitudinal vertical sectional viewof the interchangeable barrel of FIGURE 3 shown operatively positionedwithin the bore of a shotgun such as illustrated in FIGURE 1;

FIGURE 5 is a vertical sectional view taken substantially along theplane of the line 5-5 of FIGURE 4; and

FIGURE 6 is an enlarged fragmentary longitudinal vertical sectional viewof the muzzle end of the interchangeable barrel of FIGURE 3 whereindetails of the means of securing the barrel within the bore of a shotgunare illustrated.

Referring now to the drawings and particularly the exemplary embodimentof the invention illustrated in FIG- URES 1 and 2 it will be seen thatthe shotgun bore reducer indicated generally at 10 comprises a tubularbody portion 12 having an outer diameter sized so as to snugly butremovably slide within the bore 14 of a shotgun indicated generally at16. As will become apparent as the description proceeds the embodiment10 of the shotgun bore reducer of the present invention is suitable notonly for use with break-action breach-loading single barrel shotguns butalso shotguns of other types such as break-action breach-loading side byside double barrels or over and under as well as automatic andbolt-action shotguns. It will be apparent that the shotgun bore reducer10 has an external configuration generally identical to the dimensionsof a shotgun shell of the gauge which would normally be utilized withthe shotgun 16 were the reducer of the present invention not beingutilized in conjunction therewith.

Toward this end, it will be seen that the tubular body 12 of the shotgunbore reducer 10 is provided with an annular axial boss or rim 18,analogous to that normally provided on a shotgun shell casing. This rim18 is provided with an annular recess indicated generally at 20 sized soas to accept the rim of a shotgun shell such as indicated at 22 which isof a lesser gauge than that normally used in the shotgun 16.

As seen best in FIGURE 1 the shotgun bore reducer 10 is snugly butremovably received within the bore 14 of the shotgun 16 withsubstantially the entire outer surface of the bore reducer 10 in contactwith the inner surface of the shell chamber or breech end of the bore 14so as to substantially preclude undue vibration, distortion, etc. of thebore reducer 10 during utilization thereof. Moreover, as seen best inFIGURE 1 the bore reducer 10 is preferably sized so as to be slightlylonger than the shotgun shell 22 to be utilized therein so as to providea slight choke effect on the pellets passing therethrough.

From the foregoing description of the bore reducer 10 it will beapparent that inasmuch as its outer dimensions are substantially that ofa shell which would normally be utilized in the gun the bore reducer 10may be also utilized in automatic or bolt action guns inasmuch as thebore reducer 10 may be fed from the magazine, detonated and extractedfrom the gun in a manner analogous to the extension of spent shells of anormal size therefrom.

Referring now specifically to the exemplary embodiment of the presentinvention illustrated in FIGURES 36 it will be noted that the borereducer indicated generally at comprises an elongated tubular body orinterchangeable barrel member indicated at 52 of somewhat greater lengththan the over-all length of the shotgun barrel within which it is to beutilized for reasons which Will become apparent. As seen best in FIGURE3 the tubular body 52 of the elongated bore reducer 50 has a relativelylarge diameter portion 54 adapted to be positioned within the bore of ashotgun indicated generally at 56 which is substantially analogous tothe shotgun 16, for example. As will become apparent as the discussionproceeds the embodiment 50 of the present invention is not necessarilyadapted to be utilized in conjunction with automatic or boltactionshotguns but is primarily intended to be utilized in conjunction withbreak-action breech-loading shotguns. It will be appreciated of coursethat in the event it is utilized with a shotgun of other than singlebarrel construction a reducer 50 would be utilized in conjunction witheach of the barrels of the shotgun.

Referring again to FIGURES 3, 4 and 5 it will be seen that the elongatedor interchangeable barrel 52 includes a portion 58 of relatively lesserdiameter than the breech portion 54. The muzzle end 60 of the reducer 52and particularly that portion which extends outwardly from the barrel 68is externally threaded such as at 62 in order to facilitate removablysecuring the reducer 50 within the barre-l of a shogun by means of alocking collar 64 threadably received upon the muzzle end 60 of the body52 and abutting such as at 66 against the muzzle end of the barrel 68 ofthe shotgun 56. Accordingly, the muzzle portion 54 of the body 52 andits associated annular rim 55 are drawn into and against the annularrecess indicated generally at 70 within the barrel 68 normally providedfor the reception of the rim of a conventional shotgun shell so as toremovably secure the reducer 50 in the shotgun.

It will be noted that while not illustrated the portion 58 of the barrel52 could be smaller than the interior of the gun barrel 68 in order thatthe reducer 50 may be put in and taken out of the gun barrel 68 easilywhile also allowing for expansion of the barrel 52 caused by thegenerated by the firing of the gun. Furthermore, for very small gaugessuch as 410 gauge, for example, the barrel portion 58 could be of areduced outer diameter,

i.e. substantially smaller than the bore of the barrel 68 from a pointslightly in front of the shell receiving portion 54 and continuing tothe muzzle end 60. It is generally possible to reduce the diameter ofthe barrel portion 58 to smaller shotgun gauges without danger of unduevibration or the like of the reducer 5! Thus, it can be seen that it isnot necessary that the interchangeable barrel 52 fit in surface tosurface contact along the entire length of the gun barrel 68. The collar64 may be provided with an axially extending annular shoulder, notshown, in order to center relatively small diameter interchangeablebarrel within a gun barrel.

As best seen in FIGURES 3, 4 and 5 the embodiment of the shotgun borereducer 50 is preferably provided with 'a spent shell casing extractormeans indicated generally at 72 disposed within the breech end of theinterchangeable barrel 52 so as to be adapted to be operated by theshell extractor (not shown) of the shotgun 56. As seen best in FIGURES 3and 5 the extractor slide 74 is slidably received in a milled slotprovided in the body portion 54 whereby the longitudinal travel of themember 74 is limited by a pair of cars 76 projecting therefrom slidablyreceived in a circumferentially enlarged portion 78 of the slot 75.Although not specifically shown, it will be understood that theconventional mechanism of the shotgun 56 will be positioned so as tocoact with the rim of the extractor slide member 74.

As seen best in FIGURE 3 the embodiment 50 of the bore reducer of thepresent invention may further be provided with generally spiral riflingor the like as indicated generally at 80 so as to provide a means forimparting rotational motion to a slug-type shotgun projectile.

From the foregoing discussion of the bore reducer 50 and its operativeassociation with a shotgun to reduce the effective gauge thereof it willbe appreciated that the embodiment 50 of the bore reducer, by virtue ofthe fact that it extends along the entire length of the shotgun barreland is releasably secured within the bore thereof by means of athreadably secured collar 64, it substantially precludes the possibilityof subjecting the normal bore of the shotgun to what may sometimes bethe detrimental effects of fouling such as form an expanding or somewhatunchoked pellet charge. It will therefore be seen that the exemplaryembodiments of the invention illustrated and discussed satisfy theseveral objects of this invention.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is 'as follows:

1. In combination with a shotgun, a bore reducer adapted to be insertedinto the barrel of the gun to reduce the effective gauge of the shotgun,said reducer comprising an elongated tubular member having a rearportion and a forward end portion, said rear portion of said tubularmember being adapted so as to be received in the shell rim receivingrecess in the breech of the shotgun, said forward portion of saidtubular member being sized so as to be adapted to be received within thebore of said shotgun, the breech end of the bore of said tubular memberbeing provided with an annular recess adapted to receive the rim of ashotgun shell of lesser gauge than normally utilized in said shotgun,said tubular member being of sutficient length so as to extend withinand along at least the entire length of the barrel of the gun, saidforward portion of said tubular memher when operatively positionedwithin the barrel of said shotgun extending outwardly from the muzzleend thereof, said outwardly extending portion of the tubular memherbeing provided with a securing means adapted to removably secure thetubular member within the barrel of said shotgun, said outwardlyextending portion of said bore reducer being provided with externallydisposed threads and a collar adapted to be threadably received thereonso as to abut the nozzle end of said Shotgun to remov'ably secure thebore reducer within the barrel of the shotgun, a spent shell extractormeans comprising an extractor member slidably carried by said tubularmember adjacent the breech end thereof and adapted to be operativelypositioned so as to coact with the extractor means of said shotgun, saidspent shell extractor means including an open-ended slot means providedin the rear portion of the tubular member, said slot means being incommunication with the peripheral and breech end surfaces of saidtubular member, said slot means having a circumferentially enlargedportion at the forwardly disposed end thereof, said circumferentiallyenlarged portion of said slot means being provided with a pair ofcircumferentially opposed axially extending slots in noncommunicationwith the peripheral surface of said tubular member, said extractormember being slidably carried in said slot means and including a pair ofoutwardly and circumferentially disposed ears adjacent the forwardlydisposed end thereof, said ears being engaged in said circumferentiallyopposed slots whereby the travel of said extractor member is limited byaxial end walls defining a portion of said circumferentially enlargedportion.

2. In combination with a shotgun, a non-segmented tubular bore reducerhaving external dimension generally identical to the dimensions of ashotgun shell of a gauge normally utilized in the shotgun, said borereducer being adapted to receive a shotgun shell of lesser gauge thannormally utilized by the shotgun thereby adapting the shotgun tooperatively receive shotgun shells of a lesser gauge than normallyutilized therein, said reducer comprising an elongated tubular memberhaving a rear portion and a forward end portion, said rear portion ofsaid tubular member being provided with means so as to be received inthe shell rim receiving recess in the breech of the shotgun, saidforward portion of said tubular member being sized so as to be receivedwithin the bore of said shotgun, the rear portion of the bore of saidtubular member being provided with an annular recess to receive the rimof a Shotgun shell of lesser gauge, a spent shell extractor meanscomprising an extractor member slidably carried by said tubular member'adjacent the rear breech end thereof adapted to be operativelypositioned so as to coact with the extractor means of said shotgun, saidspent shell extractor means including an open-ended slot means providedin the rear portion of the tubular member, said slot means being incommunication with the peripheral and breech end surfaces of saidtubular member, said slot means having a circumferentially enlargedportion at the forwardly disposed end thereof, said circumferentiallyenlarged portion of said slot means being provided with a pair ofcircumferentially opposed axially extending slots in noncommunicationwith the peripheral surface of said tubular member, said extractormember being slidably carried in said slot means and including a pair ofoutwardly and circumferentially disposed ears adjacent the forward- 1ydisposed end thereof, said ears being engaged in said circumferentiallyopposed slots whereby the travel of said extractor member is limited byaxial end Walls defining a portion of said circumferentially enlargedportion. ml

References Cited UNITED STATES PATENTS 252,241 1/ 1882 Morris 4277282,194 7/1883 Howe 4277 640,070 12/1899 Aeschbacher 4277 783,561 2/1905White 4277 X 1,555,854 10/1925 Hill 4277 1,759,772 5/ 1930 Williams 42773,156,995 11/ 1964 Mellor et al. 4277 3,196,569 7/ 1965 Thomason 4277BENJAMIN A. BORCHELT, Primary Examiner,

